First, grate the medium zucchinis using a box grater. Place the grated zucchini into a colander and sprinkle it with one teaspoon of salt. Let it sit for about 10-15 minutes. This step is crucial because the salt will draw out the excess water from the zucchini.
After letting the zucchini rest, transfer it to a clean kitchen towel or cheesecloth. Gather the cloth and wring it out over the sink, squeezing as hard as you can to remove as much liquid as possible. You'll be surprised by how much water comes out! This is the secret to perfectly crispy fritters.
In a large mixing bowl, combine your squeezed zucchini with the all-purpose flour, grated Parmesan cheese, lightly beaten eggs, minced garlic, chopped fresh herbs, and black pepper. Stir all the ingredients together until you have a thick, well-combined batter.
Heat the olive oil in a large skillet over medium-high heat. Once the oil is shimmering, drop spoonfuls of the batter into the pan. Use the back of your spoon to gently flatten each one into a small patty. Cook for 3-4 minutes per side, until they are golden brown and crispy.
Transfer the cooked fritters to a plate lined with paper towels to absorb any excess oil. While they are cooling slightly, prepare the yogurt sauce. In a small bowl, whisk together the Greek yogurt, lemon juice, olive oil, minced garlic, salt, and pepper until smooth and creamy.